swh-dedup=# explain  select count(chunk.length)            
    from chunk tablesample system(0.001)
    left join chunked_content_chunk on chunk_id = chunk.id;
                                            QUERY PLAN                                            
--------------------------------------------------------------------------------------------------
 Aggregate  (cost=62753422.72..62753422.73 rows=1 width=8)
   ->  Hash Right Join  (cost=509.64..57923049.12 rows=1932149440 width=4)
         Hash Cond: ((chunked_content_chunk.chunk_id)::bytea = (chunk.id)::bytea)
         ->  Seq Scan on chunked_content_chunk  (cost=0.00..33529225.40 rows=1932149440 width=21)
         ->  Hash  (cost=338.73..338.73 rows=13673 width=25)
               ->  Sample Scan on chunk  (cost=0.00..338.73 rows=13673 width=25)
                     Sampling: system ('0.001'::real)
(7 rows)

swh-dedup=# \d+ chunked_content_chunk
                                 Table "public.chunked_content_chunk"
       Column       |  Type   | Collation | Nullable | Default | Storage  | Stats target | Description 
--------------------+---------+-----------+----------+---------+----------+--------------+-------------
 chunked_content_id | integer |           |          |         | plain    |              | 
 chunk_id           | sha1    |           |          |         | extended |              | 
 position           | integer |           |          |         | plain    |              | 
Indexes:
    "chunked_content_chunk_chunked_content_id_chunk_id_position_idx" UNIQUE, btree (chunked_content_id, chunk_id, "position")
    "chunked_content_chunk_chunk_id_idx" btree (chunk_id)
    "chunked_content_chunk_chunked_content_id_idx" btree (chunked_content_id)
Foreign-key constraints:
    "chunked_content_chunk_chunk_id_fkey" FOREIGN KEY (chunk_id) REFERENCES chunk(id)
    "chunked_content_chunk_chunked_content_id_fkey" FOREIGN KEY (chunked_content_id) REFERENCES chunked_content(id)